data given:

Given,

UCL_X=12.2 seconds

LCL_X=11.8 Seconds

UCL_R=0.5 seconds

LCL_R=0 second

Now ,

Caluclate and

=Average of all observation

=Average of all

Constructing X bar control chart

Now R control chart

Range=(Max-Min )of all observation

=Average of all Range

Answer b)

As per above R control chart ,One of the observation is out the control limit so process is out of control.

looking at graph how did you plug in numbers for the graph!!

Thanks!!